The present invention concerns systems having a cut-off, or shut-off, or shut-down feature. For example, the invention is applicable to product delivery systems at fixed facilities or on vehicles which deliver a product from a source, such as a tank, receptacle, or container. The product may be gaseous, liquid, solid, gel, or some combination thereof. By way of example, the product may be propane, gasoline, oil, or feed grain. Of great concern is the delivery of hazardous or combustible products which may pose safety, health or environmental threats, especially those associated with the risk of fire, explosion, implosion, toxicity, or other dangers.
Various regulations and guidelines address the concerns for safe transfer of potentially dangerous materials. For example, it has been established in 49 C.F.R. .sctn.178.337.11(a)(i) that each internal self-closing stop valve and excess flow valve must automatically close if any of its attachments are sheared off or if any attached hoses or piping are separated.
It is also known that existing self-closing and excess flow valves experience difficulty automatically operating when container volume is low and pressures are low. Thus, reliance on these types of devices might not be warranted in a wide variety of operating conditions.
A principal object of the invention is to monitor the physical integrity of a product transfer system and enable automatic termination of the transfer process in the result of separation of piping, hose or attachment within the piping system, and in particular, complete separation thereof. Another object is to provide a system to detect piping or hose break on cargo vehicles or fixed facilities. A further object is to provide a product delivery system which is continuously monitored and which has a manual safety cut-off feature.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.